The effects of alcohol, drugs (both ethical and illegal), fatigue, stress, emotional disturbance and the like have long been known to degrade both the physical and mental performance of human beings. Such degradation of performance may, in critical tasks, result in catastrophic loss of life and/or property. For example, impaired performance of an airline pilot may result in improper response to unusual circumstances or aircraft attitudes leading to a crash of the aircraft thereby resulting in total destruction of the aircraft and often loss of life to both crew and passengers. Numerous examples of such occurrences may be found by reference to the National Transportation Safety Board (NTSB) reports on aircraft accidents, both in the general and commercial aviation fields.
Impaired functional capabilities of operators of other types of vehicles can also lead to similar results, for example, bus or truck drivers carrying cargo or passengers, the operators of vessels on the high sea carrying cargo or passengers and the like. In addition thereto, individuals who are operating complex or sensitive equipment may likewise make decisions or take actions which could result in the occurrence of a catastrophic event.
Many attempts have been made directed to intrusive and non-intrusive testing of individuals to ascertain whether or not their systems contain performance degrading substances. The testing of individuals in this manner has raised many legal, ethical and moral issues and in many instances is inadequate. Particularly, such testing will not disclose degradation due to emotional disturbance, stress, debilitation as a result of age or disease or the like.
Various other attempts have been made to test individuals on a non-intrusive basis or without the necessity of testing breath or urine samples. For example, U.S. Pat. No. 3,901,215 to Erwin Roy John entitled "METHOD OF TESTING THE SENSES AND COGNITlON OF SUBJECTS" discloses a system which produces an electroencephaloqraph in response to predetermined stimuli Which response is then compared to the patient's evoked response at a base line condition to ascertain differences between the two. Any differences are automatically statistically analyzed by a computer to ascertain the significance thereof. Obviously, such apparatus requires complex sensors and a highly trained attendant to provide the stimuli to the individual and record the results emanating from the individual's brain, both to establish the base line and the response to the stimuli.
Other apparatus in the form of simulators (both automotive vehicle and aircraft) have been developed to test the capability of an operator to perform pre-selected critical tasks in advance of assuming positions to carry out such tasks. The simulators are typically programed in such a manner that the operator functions to perform tasks (driving/flying) which are normally performed in the day-to-day work of that individual. The test results are compared against proper (objective) responses expected of individuals in similar circumstances. Although such tests are generally effective, they do not compare that person's present capabilities of performance against that same person's previously established performance response abilities. Furthermore, such simulators, even the most simple ones, are relatively expensive and the utilization of them for such testing requires a substantial amount of time.